Summary of Image Types and Numeric Classes :: Displaying Bit-Mapped Images (Graphics)

Graphics

Summary of Image Types and Numeric Classes

This table summarizes the way MATLAB interprets data matrix elements as pixel colors, depending on the image type and data class.

Image Type
double Data
uint8 or uint16 Data

Indexed
Image is an m-by-n array of integers in the range [1, p].
Colormap is a p-by-3 array of floating-point values in the range [0, 1].
Image is an m-by-n array of integers in the range
[0, p - 1].
Colormap is a p-by-3 array of floating-point values in the range [0, 1].

Intensity
Image is an m-by-n array of floating-point values that are linearly scaled by MATLAB to produce colormap indices. Typical range of values is [0, 1].
Colormap is a p-by-3 array of floating-point values in the range [0, 1] and is typically grayscale.
Image is an m-by-n array of integers that are linearly scaled by MATLAB to produce colormap indices. The typical range of values is [0, 255] or [0, 65535].
Colormap is a p-by-3 array of floating-point values in the range [0, 1] and is typically grayscale.

RGB (Truecolor)
Image is an m-by-n-by-3 array of floating-point values in the range [0, 1].
Image is an m-by-n-by-3 array of integers in the range [0, 255] or [0, 65535].

Image Type	double Data	uint8 or uint16 Data
Indexed	Image is an m-by-n array of integers in the range [1, p]. Colormap is a p-by-3 array of floating-point values in the range [0, 1].	Image is an m-by-n array of integers in the range [0, p - 1]. Colormap is a p-by-3 array of floating-point values in the range [0, 1].
Intensity	Image is an m-by-n array of floating-point values that are linearly scaled by MATLAB to produce colormap indices. Typical range of values is [0, 1]. Colormap is a p-by-3 array of floating-point values in the range [0, 1] and is typically grayscale.	Image is an m-by-n array of integers that are linearly scaled by MATLAB to produce colormap indices. The typical range of values is [0, 255] or [0, 65535]. Colormap is a p-by-3 array of floating-point values in the range [0, 1] and is typically grayscale.
RGB (Truecolor)	Image is an m-by-n-by-3 array of floating-point values in the range [0, 1].	Image is an m-by-n-by-3 array of integers in the range [0, 255] or [0, 65535].

Converting an 8-Bit RGB Image to Grayscale Reading, Writing, and Querying Graphics Image Files